When the written language that children learn to read and write is distinct from the oral language they acquired as their mother tongue, they may encounter substantial challenges. The linguistic distance between two varieties of the same language could have an impact on the literacy acquisition journey. The present study focuses on Arabic, a prototypical case of diglossia, where the distance between the spoken and standard varieties has been intensively examined phonologically and lexically. However, a paucity of studies has addressed their morphological distance. This study takes one step in this direction by describing, analyzing, and quantifying the distance of morphemes in content words from spoken Palestinian dialect (SPD) to Modern Standard Arabic (MSA). It is the first to map this distance by form and function in the three predominant systems: derivation, inflection, and clitics in nouns and verbs. All morphemes were arranged on an axis targeting four main levels that varied in the extent of the morphological distance from SPD to MSA, beginning with 'identical' morphemes (same form, same function), followed by 'strongly overlapping' morphemes (morpho-phonological difference in form, same function), then 'partially overlapping' morphemes (different form, same function), and ending with 'unique' morphemes (unique form, same/different function). The mapping showed significant findings indicating that most morphemes are non-identical between SPD and MSA, comprising 81.4% of the total. Most of these non-identical morphemes (64.9%) were assembled to the 'partially overlapping' and 'unique' levels, appearing mainly in the verb inflection category. Implications for the possible impact of morphological distance on reading acquisition are discussed.